This invention relates to the field of automative door opening and closing systems, and particularly to an integrated system of components that transport an automotive sliding door through its range of motion while providing adequate user safety.
Sliding doors are widely used on the class of vehicles generally referred to as vans. Vans typically have normal swinging front doors and one or more sliding side doors. These types of sliding doors translate out of the side opening in the vehicle to facilitate ingress/egress rather than rotating, as is the more common motion of automotive closures. The most common and widely used sliding door system consists of three body-mounted tracks (3) and three corresponding door-mounted hinge/roller assemblies (15), as illustrated in FIGS. 4 and 5. The body mounted tracks are normally located at the roof, floor and mid-positions on the side of the vehicle with the roof-position and floor-position components being arranged in-line with the door opening and the mid-position (centre) track located rearward of the side opening. It is normal practice to utilize the lower and centre tracks to carry the vertical weight of the door. The travel path of the door is therefore defined by the track shape and articulation of the hinge/roller assemblies.
Power closing and opening of automotive sliding door systems has become a popular feature. The present state of the art involves use of electrically driven systems that power the door through the range of motion defined by the conventional hinge/roller/track system. The majority of such systems act on the centre hinge/roller/track assembly although some are integrated with the lower hinge/roller/track assembly. Both belt and cable drives are utilized. In addition to powering the door though its range of motion, these systems must provide protection against injury when obstructed during powered movement and normal manual operation capability when required.
Current state of the art sliding door powered opening and closing systems use sophisticated electronic hardware and software algorithms to achieve acceptable levels of obstruction detection. The most common method of protection utilizes drive motor electrical current sensing to indicate when a person or other object is in the path of the closing door. The associated software algorithms are becoming increasingly sophisticated to coordinate hold-open latches, power pull-in latches, and other additional features. A major drawback of all existing art is that it does not provide manual operation performance equal to passive systems since some additional power related components are always engaged even when the sliding door is manually operated. Clutch disengagement upstream of the cable or belt drive is the most common manual operation mode, which adds significant operating load due to the associated friction with such mechanisms and operations.
Accordingly, it would be advantageous to create a sliding door opening and closing system which does not suffer from the drag and friction associated with engagement of power related components even when the door is in manual operation.
The present invention is targeted at reducing the complexity of automatic sliding door opening and closing systems. It specifically eliminates electronic obstruction detection by utilizing a mechanical arrangement and additionally provides uncompromised manual performance by completely decoupling the power system.
In a major aspect of the invention, an automatic sliding door opening and closing system comprises a continuous, powered belt drive system located on a vehicle body; and a clamp arrangement capable of fixably attaching a vehicle door to the belt drive system so as to be automatically driven along a predetermined path and capable of releasing under predetermined conditions.
In a further aspect, the powered belt drive system is located so as to be combined with one of a standard hinge system""s three body tracks. In a further aspect, the clamp arrangement is attached directly to one of the standard door hinge/roller assemblies on the door. In a further aspect, the clamp arrangement is a rotary device biased into a pinching action on the belt via a cam and spring arrangement, and the rotary device is arranged so as to release from the belt at a predetermined force threshold. In a further aspect, the powered belt drive system incorporates two belt tensioning devices, located on opposite sides of the clamp arrangement, capable of providing the required belt slack to facilitate movement of the rotary clamping device into a pinching engagement with the belt.